Terrace cleaning

Last summer the terrace was a place you sat. This year it is a place you walk quickly past, because the boards are grey, become slippery after rain, and have grown green-black patches on the north side where the sun never reaches. You have considered pressure-washing it yourself. The neighbour did, and his terrace came out brilliantly clean for two weeks — and then fuzzy, grey and worse than before.

That is not a coincidence. It is what high pressure does to wood.

What we actually do

The principle is simple: chemistry and time do the work, not pressure.

1. Clearing and sweeping. Leaves, pine needles and debris between the boards are removed. The gaps between the boards are where moss starts, and a terrace cleaned without clearing the gaps will be green again by autumn.
2. Plants and beds are covered and watered before any product is applied. Wet foliage absorbs less chemical.
3. The timber is assessed. Age, wood type, previous treatment and any rot. A board that has rotted should be replaced, not washed — we tell you if that is the case.
4. Algae-killing product with dwell time. The product is applied evenly and allowed to work its way into the outermost layer. This is where the work happens. Moss is a living organism, and it must be killed, not merely rinsed away — otherwise it grows back from residue in the pores.
5. Gentle washing at low pressure, along the grain. Where moss sits stubbornly, we scrub by hand instead of turning up the pressure. Always.
6. Railings, posts, steps and the underside of the lower board edge are included — this is where moisture and moss gather first.
7. Rinsing of the terrace and the surrounding surfaces, so no product is left on stone or lawn.

Why it pays off

Moss and algae hold on to moisture. Damp wood is wood that rots, and that freezes and expands in winter so the boards crack. It is also slippery — an algae-covered terrace in autumn rain is one of the most common places people fall at home.

Then there is the oil. The point of cleaning is not only that the terrace becomes light. It is that clean, dry timber takes oil evenly, while grey, algae-covered timber does not. Oil applied to an unwashed terrace settles over the algae, seals in moisture, and flakes off in uneven patches the following spring. Clean first, oil after — in that order the treatment lasts several seasons.

And finally, pressure. A terrace that has been pressure-washed is not just roughened on the surface; it has had the hard autumn wood between the growth rings stripped away, and so absorbs water faster forever afterwards. It is an irreversible shortening of the terrace's lifespan, done in an afternoon.

How often should you have it done?

Once a year, preferably late spring. If the terrace stands in shade or under trees, every season may be right. Oil it after each cleaning, and each cleaning becomes easier than the last.

How long does it take?

Around 4 hours for a normal terrace, depending on area, railings and how long it has been since last time. The dwell time of the product cannot be rushed.

Book an inspection for terrace cleaning — you receive a fixed price in writing within one working day.